Pedro I was the only legitimate son of Alfonso XI, who had left five illegitimate sons by his mistress, Leonor de Guzmán, to each of whom he had given important holdings and titles. On the death of Alfonso, his wife (Pedro’s mother) procured the arrest of Leonor de Guzmán and later her assassination. Naturally, this incensed the five sons of Leonor, although all but the eldest, Count Henry of Trastamara, appeared to accept the situation. Other pretexts for internal strife were not lacking. Pedro was a mere boy, and at one time became sick and seemed about to die, whereupon the nobles began to prepare for a dynastic struggle. Pedro lived, however, but caused discontent by choosing a Portuguese, named Alburquerque, as his leading adviser and favorite; the chief basis for the objections of the nobles was that each one wished the post for himself. The resistance to Alburquerque was the rallying-cry in the early period of the wars, in which Pedro’s illegitimate brothers joined against him. Pedro was successful, and it is noteworthy that he dealt leniently with his brothers, in contrast with his energetic cruelty against the other rebels. In 1353, as the result of negotiations which had been arranged by Alburquerque, Pedro married a French princess, Blanche of Bourbon. Previously, however, he had entered into relations with a handsome young lady of good family, named María de Padilla, to whom he remained ardently devoted for the rest of his life. So blindly in love with her was he that Alburquerque had to take him from the arms of María in order to have him assist at his own wedding. Three days later the youthful Pedro deserted his wife in favor of his mistress. Alburquerque wisely took himself away, the Padillas were established as the favorites at court, and the young queen was imprisoned. The nobles could no longer pretend that they were fighting Alburquerque; on the contrary, they joined the very man they had assumed to oppose, in a war against the king, with various alleged objects, but in fact with the usual desire of seizing an opportunity for increasing their own power. At one time they contrived to capture Pedro, but he escaped and wreaked a fearful vengeance on his enemies, though once again he allowed his brothers, who as usual were against him, to submit. Meanwhile, Pedro’s marital experiences included a new wife, for he found two bishops who declared his first marriage null, despite the pope’s efforts to get the king to return to Blanche of Bourbon. Pedro married Juana de Castro, but this time was able to wait only one day before returning to María de Padilla. These events had their influence in the civil wars, for many towns refrained from giving Pedro aid or joined against him out of disgust for his actions. [Sidenote: The wars with Henry of Trastamara.]